Spall-burning kiln



Dec. 2, 1930. M. E. SQUIRE 1,783,632

SPALL BURNINGKILN Filed Nov. 25, 1927 v2 Sheets-Sheet 1 I v I I Z? fl,1 I g0- INVENTOR.

BY Y #W Y AT. ORNEYS Dec. 2, 1930. M. E. sQLHRE v SPALL BURNING, KILNV 2 Sheets-Sheet 2 Filed Nov f as. 1 927 INVENTOR;

7 I W ArToRNEys adheres to the sides Patented Dec. 2, 1930 UNITED STATES FATE NT "OFFICE srALnBURNinG KILN Application filed November 25,219,27. Serial No. 235,604.

This invention relates to improvements in spall burning kilns.

Heretofore, lime kilns have been so constructed that material fed into the upper portion of the kiln will descend without interference, thereby bunching together, causing a stoppage in the kiln, and preventing the draught and flames from crossing the kiln and from cominginto' contact with all of the material.

It is one of the objects of this invention to obviate the above objectionable feature and to provide an improved spall burning kiln in which the inner walls are ofa novel tapering construction to allow the material to descend gradually and toroll and change place in so doing, and also to cause the draught and flames to cross the kiln in their ascent to distribute the heat throughout the descending material.

It is a further object of this invention to provide an improved spall burning kiln in which poke holes are provided to allow the material'to be released if for any reason it of the kiln in such a manner as to cause a stoppage.

It is a further object to provide a lime kiln having observation apertures to permit a view of the interior of the kiln when desired.

It is a further object of this invention to provide doors near the outlet to control the discharge of the material.

It is a further object of this inventionto provide a spall burning kiln which is simple in construction and operation and Well adapted to the purpose described.

With the above and other objects in View, the invention consists of the improved spall burning kiln, and all its parts and combinations as set forth in the claim, and all equivalents thereof.

In the accompanying drawings, in which the same reference characters designate the same parts in all of the views:

Fig. 1 is a vertical sectional View of the kiln taken on line 1-1 of Fig. 2;

Fig. 2 is a vertical sectional view taken at right angles to the view in Fig. 1;

Fig. 3 is a sectional View taken on line 33 of Fig. 1;

Fig. 4: is a sectional View taken on line 4 4 of Fig. l; r

Fig; 5 is a plan view of thekiln; and

Fig. 6 is a fragmentary detail View of a lower portion of the kiln. j 1

Referring to the drawing',-the numeral 10 designates thekiln generally, which is con: structed preferably of brick with liningsof fire brick. The kiln is formed with anlnterior opening 11 which is much wider in one direction than in the other as may readily be seen from-Figs. 1 and 2. Furthermore, as shown in Fig. 1, the opening diverges from the top and bottom to form a widened central' portion. By examining Fig. 2, it may be noted that the opening extends vertically for a distance of about one-third of the height of the kiln,.and then inclines to one side at an angle of approximately At: a'point medial of the height of the kiln, again extends substantially vertically towards the bottom. Below the inclined portion ,there are recesses in the inner walls forming combustionchambers 12. Gas flues 13, and gas ports 14 are located in an inter- 7 mediateportion of the kiln. To allow an inspection of the interior of the kiln when desired, sight holes 15, which are normally? closed by plugs 16, are provided. Poke holes 17, the sides of which diverge inwardly, allow movement of a poker in all directions, to release material which has caused a stoppage. These holes are also provided with plugs.

In the lower portion of the kiln, a midfeather l8 divides the descending material into two parts, and allows half to be discharged through the draw hole 19, and half through the draw hole 20. The draw holes are provided with doors 21. These doors do not fully close the openings but leave a space 22 which permits the lime to be discharged gradually. It is not desirable, under ordinary conditions, to permit a large quantity of lime to accumulate at the draw holes. If, however, for any reason it is necessary to discharge a large amount, the doors may be swung open by manipulating the handles 23, which project from the side of the kiln. Stops 24 are provided for these handles.

The operation of the kiln is as follows: I

the opening Material, generally limestone spalls, is fed into the upper end of the opening 11. The material falls through the vertical portion until it reaches the incline. This slows up its descent, and causes the material to roll down and change its position in so doing. In order to calcine the material, gas is introduced into the ports 14: at a temperature nearly equal to that at which it is produced. A saving of time and fuel is effected by this maximum temperature, preventing the condensation and deposit of any of the hydro-carbons. There is therefore no necessity for so frequent cleaning of the passageways. The draught and flames from the ignited gas will cross the kiln in their ascent, due'to the incline in the passageway. This insures a thorough distribution of the heat throughout the material. The finished product finally falls through the space 22 into the draw pit, from which it is removed. As before stated, When the doors 21 are closed, only a small amount of material may be discharged at a time.

From the foregoing description, it may be readily seen that the improved kiln is provided with a very novel interior opening, that it is simple in construction, and well adapted for the purpose described.

hat I claim is:

A kiln comprising a casing having an interior passageway, there being a feed opening and a. discharge opening in connection with said passageway, said passageway comprising an upper substantially vertically extending chamber having one pair of opposite walls diverging downwardly, an intermediate chamber of a uniform width equal substantially tothe distance between the lower portions of the diverging walls of the upper chamber, said intermediate chamber extending at an angle with respect to the upper chamber, and a lower chamber extending substantially vertically from said intermediate chamber and having one pair of opposite walls converging downwardly.

In testimony whereof, I afiix my signature.

ARY E. soumn. 

